Messrs. Henry J. Elwes and James Edwards have carefully studied the species of the genus Ypthima and have published the important results of their researches in the Transactions of the Entomological Society of London, 1893, part I, pp. 1—54. The limited acquaintance with the Dutch language and the want of sufficient Javanese material have prevented the above named authors from doing justice to the species, described by the late Mr. P. C. T. Snellen in the „Tijdschrift voor Entomologie", XXXV, pp. 133 and 135. In recent years, 1910 and 1913, Messrs. H. Fruhstorfer and M. C. Piepers have maked a more particular study of the Indo-Australian and Javanese species of Ypthima. The results of Mr. Fruhstorfer's researches are published in the work of Prof. A. Seitz, and those of Mr. Piepers' in „The Rhopalocera of Java".The latter has not examined the anatomical characters and has separated the Javanese species, just as Mr. Snellen did, by the outward morphological characters only. The work of Messrs. Elwes and Edwards has undoubtfully shown to us the great systematic value of the modification of the male genitalia. Arranging the large number of Javanese Ypthimaspecimens in the collection of the Leiden Museum of Natural History, I have taken the fortune at the tide to examine the male genitalia of the species not examined by Messrs. Elwes and Edwards, and to compare the descriptions in the four named publications.Ypth. fasciata Hew.Hewitson, Trans. Ent. Soc. of London, (3) 2, p. 287, 1864. — Elwes and Edwards, l. c. 1893, p. 44. — Fruhstorfer, Seitz, Grossschm. IX, p. 237, pl. 99 g, 1910. — Piepers and Snellen, Rhop. of Java, Dan.,